| BEN |
| BOTANICAL ELECTRONIC NEWS |
|---|
| ISSN 1188-603X |
| No. 351 October 25, 2005 | aceska@telus.net | Victoria, B.C. |
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Earlier this year, on February 10, 2005, George W. Douglas died. A BEN article in March commemorated George W. Douglas for his contributions to botany in British Columbia (BEN no. 344, March 14th, 2005), but did not include a complete list of George's publications. The list of George's publications is a lengthy one and it is now available at http://www.ou.edu/cas/botany-micro/ben/suppl/351/gwdouglas.html
George W. Douglas was indeed a prolific author. He started publishing in the early 1970's upon completion of his M.Sc. and Ph.D. theses on subalpine and alpine plant communities. In the 1970's alone he produced 29 publications for journals and papers for government. In the 1980's he kept up his momentum and continued to produce many articles and government documents. He also edited and contributed to an attractive and informative coffee table book on Kluane Park, Yukon called Kluane, Pinnacle of the Yukon (Theberge and Douglas Eds. 1980). His work in the Yukon also resulted in Rare Vascular Plants of the Yukon (Douglas et al. 1981). He was a co-author of Rare Vascular Plants of British Columbia. His taxonomic passion was the Asteraceae family that resulted in The sunflower family (Asteraceae) of British Columbia, published by the Royal British Columbia Museum. Unfortunately, only the first two volumes of this three-volume work were published. In addition, in the 1970's and 80's he also made several contributions to the flora of Washington.
In the 1990's, however, his focus shifted, and he began to spend more time documenting the flora of British Columbia with special attention to the rare plants. In the 1990's, he started his work with the Conservation Data Centre (CDC) as the Program Botanist. During this time, he completed the 4-volume Vascular Plants of British Columbia and started to work on the 8-volume Illustrated Flora of British Columbia. From the mid-1990's he authored or co-authored no less than 36 species status reports, more than any other contributor of reports to the Committee on the Status of Endangered Wildlife in Canada species assessment team. In the production of the status reports, he gave many of us the opportunity to get some experience with writing and submitting articles for publication, not to mention learning a lot about a single species biology, distribution and status in British Columbia. He was also involved in the following field guides in the 1990's: Plants of Northern British Columbia (MacKinnon et al. [eds.] 1992), Plants of the Southern Interior of British Columbia (Parish et al. [eds.] 1996), and the second, expanded edition of the Mountain Plants of the Pacific Northwest (Taylor and Douglas 1995). In total, he contributed around 45 publications during the decade which greatly enhanced our knowledge of vascular plants in British Columbia and the Pacific Northwest.
In the new millennium, George retired from the CDC and started consulting. In his new capacity as a consultant to government, he became active in many projects producing many reports. In the last two years, he worked on numerous status reports, four recovery strategies for species at risk and one multi-species recovery strategy. Sadly, his life and work were cut short by a terminal illness. He has, however, left us a truly inspiring legacy of getting the work done and making it accessible. His contributions are used often by many in British Columbia and beyond.
Trisetum Pers. is a genus of about 70 species of grasses distributed in temperate regions of Europe, Asia, America, Australia and New Zealand (Finot et al. 2004). There are 40 species and several infraspecific taxa in North, South, and Central America (Finot et al. 2003, 2005). In North America north of Mexico, six native and two introduced species are recognized (Finot et al. 2005). In the Illustrated Flora of British Columbia (Douglas et al. 2001), three species were accepted; T. wolfii Vasey, T. spicatum (L.) K. Richt, and T. canescens Buckl. (including T. cernuum Trin.). Trisetum is distinguished from other grass genera in British Columbia by the combination of the following characters: small spikelets with 2 or 3 florets, glumes 2-9 mm long, and awns that are attached on the upper third of the lemma (Douglas et al. 2001).
Trisetum wolfii (Wolf's trisetum) is sometimes treated in a segregate genus, Graphephorum Desv., characterized by entire lemma apices (vs. bidentate in Trisetum s.str.), paleas tightly enclosed by the margins of the lemmas (vs. paleas not tightly enclosed by the margins of the lemmas in Trisetum s.str.), and awns that are reduced to an apical mucro (e.g., Finot et al. 2005), but most authors include it in Trisetum (e.g., Douglas et al. 2001). According to the Rare Native Plants of British Columbia (Douglas et al. 2002), T. wolfii is known from only three locations in British Columbia; one in the interior of the province, and two near the British Columbia/ Alberta border in southeastern British Columbia.
Trisetum spicatum (spike trisetum) is a cosmopolitan and morphologically variable species that is distributed widely across British Columbia. Within T. spicatum several intraspecific taxa have been described, but they are difficult to distinguish from one another due to considerable overlap in the characters (Finot et al. 2005).
Trisetum canescens (tall trisetum) and T. cernuum (nodding trisetum) are morphologically similar taxa distributed in western North America. Trisetum canescens is distributed from central British Columbia to California, while T. cernuum is distributed from Alaska to California (Rumely, in press). The taxa have been separated based on several morphological characteristics, including the morphology of the panicle, the degree of pubescence of the leaf blades, and the length of the lower glumes. Trisetum canescens is characterized by narrow panicles with spikelets to the base of the lower branches; leaf blades that are pubescent, scarcely or densely pilose, or occasionally glabrous; and lower glumes that range in length from 3-5 mm. Trisetum cernuum is characterized by more open panicles, with the lower branches usually naked on the lower third; leaf blades that are glabrous; and lower glumes that range in length from 0.75-3 mm. Most authors have recognized these taxa as distinct entities at the specific level (e.g., Louis-Marie 1928-29; Hitchcock 1950; Wilken 1993; Rumely in press), but some have recognized them as varieties (e.g., Beal 1896) or subspecies (e.g., Finot et al. 2005). In British Columbia, the taxa have been variously recognized as species, subspecies, and varieties. In the Illustrated Flora of British Columbia, Douglas et al. (2001) lump them and recognize only one taxon (T. canescens), with no mention of intraspecific variability. If only one taxon is recognized, the name T. cernuum, published in 1830, has priority over the name T. canescens, published in 1862. In Grasses of the Columbia Basin of British Columbia, Stewart and Hebda (2000) treat these taxa as varieties (T. cernuum var. canescens (Buck.) Beal and T. cernuum var. cernuum ). Calder and Taylor (1965, 1968), in the Flora of the Queen Charlotte Islands, treat these taxa as subspecies (T. cernuum Trin. subsp. cernuum and T. cernuum Trin. subsp. canescens (Buck.) Calder & R. L. Taylor).
While annotating grasses in the UBC herbarium I was able to study morphological variability within the T. cernuum /T. canescens complex in British Columbia. Based on examination of over 125 specimens, I was able to easily assign most individuals to one of the two taxa using the characteristics mentioned above, but some intermediate specimens (i.e., with combinations of characters not assignable to either taxon) were encountered. For example, Mueller-Dombois 118-6 (UBC) and Biel 773 (UBC) have open panicles and naked lower branches (typical of T. cernuum s.s.), but have lower glumes up to 4 mm (typical of T. canescens). Calder and Taylor (1968) noted this overlap in glume length in British Columbia material, and the ranges of variation in this character also overlap in the morphological descriptions provided by Finot et al. (2005). Characterizing panicle morphology in some specimens can also be subjective. The occasional overlap of glume length and somewhat variable panicle morphology do not support recognition of these taxa as distinct species, but the differences merit intraspecific recognition, since many individuals can confidently be assigned to one of the morphological groups. A recent revision of Trisetum (Finot et al. 2005) recognizes these taxa as subspecies in North America, and I follow this treatment here. To facilitate recognition of these intraspecific taxa, I present a revised taxonomic key to Trisetum in British Columbia. Complete synonymies and morphological descriptions for the taxa can be found in Finot et al. (2005).
Trisetum flavescens (L.) Beauv. (yellow oatgrass) is a species native to Europe, west Asia, and north Africa (Rumely, in press). It has been introduced into North America as a forage grass, but is not common. A collection of this species from Saanichton, Vancouver Island (Foster s.n. in 1939) is present in the UBC herbarium. The sheet was annotated verosimiliter cultum (most likely cultivated) by Bernard Boivin in 1969-70. It is possible that additional collections of this species from British Columbia will be found in herbaria.
Another species, T. orthochaetum Hitchc., thought to be a hybrid between T. wolfii and T. cernuum, was originally known only from the type specimen, collected in 1908 in northwestern Montana at Lolo Hot Springs in Missoula county near the Montana/ Idaho border. The species was rediscovered at this location in 1986 (Shelly 1987). Collections of this species made in 1994 were recently reported from Glacier National Park in Glacier Co., along the southwest side of Swiftcurrent Lake (Lesica 1998), near the Montana/Alberta border. Trisetum orthochaetum is distinguished from T. cernuum by its shorter, nearly straight awns (Finot et al. 2005). It is possible that focused searches in southeastern British Columbia or southwestern Alberta (Waterton Lakes National Park) might also discover this species in Canada, but to date no collections have been made in Alberta or British Columbia.
Taxonomic Key to Trisetum in British Columbia
[adapted from Finot et al. (2005), Douglas et al. (2001), and Rumely (in press)]
Another masterpiece of photography and graphic design is this
third and final volume on the bryophytes of the southwest German
state of Baden-Württemberg. The moss tomes are themselves part
of a larger, monumental series, which could summarily be styled
the Biodiversity of Baden-Württemberg; it has already provided
us with a work on lichens (in 2 volumes, by V. Wirth),
macrofungi (in 4 volumes, by G.J. Krieglsteiner), vascular
plants (in eight volumes, by O. Sebald et al.), lepidoptera (in
no fewer than 10 volumes, by G. Ebert) as well as bees, beetles,
birds, dragonflies, grasshoppers and mammals, oh my! All are
spectacularly well illustrated with colour photography of the
finer sort and raster dot maps of the occurrence, historical and
current, of the organisms under study, within Baden-Württemberg.
All are also useful far beyond their rather small study area.
The present volume covers the genus Sphagnum, hepatics and
hornworts of BW, totalling 223 species. The majority of species
are depicted with colour photographs. An account is provided of
the morphology, ecology, general distribution, distribution in
BW, and conservation status of each species. Original keys
accompany each genus. The accounts for individual genera were
written by different experts on those groups; a total of seven
authors, including the editors, were involved in preparing the
present volume. A 35-page bibliography opens the way into
further studies and provides background to the authors'
insights.
At Eur 49.90 a good buy, and a must-have on the shelf of any
serious bryologist, particularly those working on central
European bryophytes.
Two-thirds of this book is about self-incompatibility systems,
their genetics, evolution, and molecular biology. It provides a
concise summary of modern knowledge and hypotheses. In the 52
pages about homomorphic self-incompatibility, Darwin is cited
six times, five of them irrelevant or tangential, in a feeble
attempt to link him with a phenomenon which he identified but
did not really study per se.
Two-thirds of the rest of this book is about inbreeding
depression, and the population genetics of inbreeding
depression. There is a nice summary of Darwin's studies of
inbreeding, and a six sentence summary of current evidence. It
then plunges into population genetics more advanced than 98% of
university biology graduates would ever have seen. But you can
ignore the math and read the text.
Two-thirds of the rest of this book equals seven pages about
pollination. Included are a very brief summary of Darwin's and
modern work on pollination biology. There is a small, apparently
random, sample of other topics such as how far pollen is
transported and the inverse correlation between inbreeding and
flower size. Not mentioned are any of the fairly numerous
studies correlating selfing rate and heterozygosity with
dichogamy, stigma-anther separation, and flower color.
The remaining four pages define the four -oecies: dioecy,
monoecy, gynodioecy, and androdioecy. There is a five sentence
summary on their maintenance and evolution, and a two page
discussion of whether there is a correlation of floral
dimorphism with polyploidy. Enantiostyly gets six sentences, the
last one being, "As Darwin did not consider these systems, we
shall examine them no further". Gynodioecy (populations composed
of hermaphrodites and females) only gets two sentences, and
Darwin (1877) did a lot of work on it. Furthermore, there is a
lot of theoretical work on the population genetics of inbreeding
depression and evolution in gynodioecious plants, as well as
experimental studies in greenhouse and nature, e. g.,
Charlesworth (1981), Schultz and Ganders (1996). There has been
similar work done on dioecy. The genetics of dioecy in plants is
not mentioned except to state that sex chromosomes are rare. The
multiple sex chromosomes in polyploid Rumex and bizarre sex
chromosomes of mistletoes are not mentioned. One would have
thought that this work integrating genetics, inbreeding
depression, evolution, and testing Darwin's hypotheses would
have fit in this book perfectly. It deserved mention more than
enantiostyly did.
The book is written in the same style as my review, so it is not
an entertaining read. The text is compressed, declarative, short
on discussion and examples.
The title and subtitle on the front cover, Outbreeding
Mechanisms in Flowering Plants, An Evolutionary Perspective from
Darwin onwards, sound comprehensive and general. On the back
cover the truth is told, "The envisaged readership encompasses
academics, research students (from the end of the first degree
upwards) and research workers in the plant sciences". The book
is not meant to be very accessible to general readers. In their
introduction Leach and Mayo state, "In our book, we aim to
describe the present state of understanding of the effects of
inbreeding, and of the genetics of the outcrossing mechanisms
that Darwin (1877) studied, together with related mechanisms
that he could not investigate without statistics or Mendelian
genetics or molecular biology". My disappointment with the book
is that they do not fulfill their aim. There is too much that is
missing. If the book had been called "Self-incompatibility and
inbreeding depression" the gaps would not have been so glaring.
The attempt to use Darwin as a unifying feature of the book also
fails because so much of the book is about self-incompatibility,
and so much of Darwin's work on other outbreeding mechanisms is
omitted. The book seems to me to be a text for a graduate course
on the authors' two favorite subjects.
There is a nine page appendix listing species Darwin considered
in his two most relevant books (Darwin 1876, 1877), and giving a
more recent reference in most cases. Erythroxylum and
Amsinckia spectabilis are omitted, among others, and
Pulmonaria is mistakenly called tristylous. The point of this
appendix is not clear, unless it is to prove that Darwin studied
a lot of plants. The references given are usually not the most
recent, or comprehensive, or significant.
My last complaint concerns a subject that has bothered me for
more than 30 years, the confusion of self-incompatibility with
interspecific uncrossability, also called interspecific
reproductive isolation, interspecific incompatibility (which may
be at the root of the confusion), or incongruity. Hogenboom
(1975) pointed out the differences, and coined the term
incongruity for interspecific failure to cross, to try to
clarify that these phenomena were not the same. De Nettancourt
(1977) rejected Hogenboom's arguments. As I pointed out in my
review of de Nettancourt's book (Ganders 1978), the only
evidence that self- incompatibilty genes are involved in
interspecific reproductive isolation comes from the special case
where self-compatible species are closely related to and most
likely derived from self- incompatible species. Crosses with the
self-compatible species as the pollen parent fail while the
reciprocal cross succeeds. Everyone agrees that in this case the
self-incompatibilty genes may be involved. (Other
interpretations are also possible, however. The self-compatible
species usually have smaller flowers with shorter styles, so
their pollen may not be able to grow through the longer styles
of their self-incompatible relatives.) It is not at all obvious,
however, that there is any connection between this phenomenon
and the failure of crosses between different species of closely
related, self-compatible annuals. And in many cases, closely
related perennials do cross successfully no matter what their
incompatibility behavior is. Failure of more distantly related
species (in different genera or families)to cross successfully
was viewed by Darwin as a byproduct of evolutionary divergence
which may affect any aspect of the relationship between pistil
and pollen. There still isn't any good evidence that self-
incompatibilty genes are involved in this kind of interspecific
reproductive isolation. This was Hogenboom's view and my view
and the view of most plant biosystematist-evolutionists. It
seems not to be the view of many incompatibility system
geneticists, who seem either to not distinguish these different
cases, or are wedded to the belief that self-incompatibilty
really must be responsible for interspecific reproductive
isolation, despite the lack of evidence. Leach and Mayo
repeatedly confuse them, although on page 28 (not in the
incompatibility chapter) they do admit that "floral traits
important in reproductive isolation do not appear to have been
considered likely to involve self-sterility".
The best part of this book is the modern discussion of what is
known about self-incompatibility. What is now known bears little
relationship to what was hypothesized almost three decades ago
(de Nettancourt 1977). Although current understanding of self-
incompatibility is still very incomplete, the contrast is
striking. However, this book assumes the reader has a good
background in the subject. It is not easy material, and it is
not presented in an introductory way.
1. Lemma awnless or with awns rarely exceeding the lemmas
................................................ T. wolfii
1. Lemmas awned, the awns far exceeding the lemmas.
2. Panicles contracted and spikelike; upper glumes not much
longer than lower glumes .................. T. spicatum
2. Panicles open, erect or lax; upper glumes much longer than
lower glumes.
3. Ovary and caryopsis glabrous near the apex; upper
glumes equal to or longer than the lowest florets
...................................... T. flavescens
3. Ovary and caryopsis hairy near the apex; upper glumes
shorter than the lowest florets.
4. Awns 3.5-4 mm long, straight, shorter than the
lemma; apex of the lemma shortly bidentate; first
glumes 4-6 mm long, never rudimentary
................................. T. orthochaetum
4. Awns 6-16 mm long, geniculate, one to three times as
long as the lemma; apex of the lemma ending in two
setae, 0.5-1.5 mm long; first glumes 0.5-5 mm long,
sometimes rudimentary
5. Panicles few-flowered, open; lower branches
usually naked on the lower third; leaf blades
glabrous, lower glumes 0.75-3 mm long
.................. T. cernuum subsp. cernuum
5. Panicles densely flowered, narrow; branches
closely appressed, the lower ones usually with
spikelets to the base; leaf blades pubescent,
sparsely to densely pilose, or glabrous; lower
glumes 3-5 mm long
................ T. cernuum subsp. canescens
Acknowledgements
This work was supported by a research assistant position funded
by the UBC Department of Botany. I thank Cindy Sayre for
assistance in the UBC herbarium, and Sean Graham and Adolf Ceska
for comments that improved the manuscript.
References
MOSSES OF BADEN-WUERTTEMBERG SERIES NOW COMPLETE
From: Toby Spribille [tspribi@uni-goettingen.de]
NEW BOOK: OUTBREEDING MECHANISMS IN FLOWERING PLANTS
From: Fred R. Ganders, Dept. of Botany, Univ. of British Columbia, Vancouver, B. C. V6T 1Z4 [ganders@interchange.ubc.ca]
References
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